investigation if needed, and we know that president putin here has spoken to president obama on friday, that he expressed his condolences on behalf of the russian people and that the two agreed to stup up cooperation on counterterrorism. >>> sky news's kati stallard in moscow. thank you very much. >>> this morning the boston transit police officer who was wounded in the shoot-out with the bombing suspects is in critical but stable condition. richard donahue loft nearly all his blood and had to have his heart restarted after his heart stopped and he's on a breathing machine. >> he was doing his job. the subsequent event showed us how heroic and dedicated an officer he is. he engaged the terrorist in the most difficult of situations that none of us can begin to imagine. >> donahue was responding to a call for assistance from the m.i.t. police. it was his friend and classmate police officer sean collier who ha mortally wounded. >>> the london marathon was run yesterday without incident. before the race started, runners observed a moment of silence in honor of the boston victims. there wer